Sideboarding is one of the most important and trickiest aspects of competitive Constructed Magic. There is the running joke that sideboarding is just “taking out the bad ones and putting in the good ones.” While that is essentially true, there’s a lot more to it than that. People tend to write about sideboarding in the context of a specific format or deck, but I want to talk about the process more broadly.
Let’s look at how to build a sideboard for maximum effect. When I build a sideboard, I consider the specific tournament metagame, the common matchups and interactions of the format, and how to keep my sideboard cards as flexible as possible.
Specify Your Metagame
Sideboards are designed to adapt your deck to the other decks you might face in a tournament. The metagame defines the decks you can expect to see and thus need to build your sideboard around. Modern has a general metagame in the broad sense, but individualy tournaments vary quite a bit. Knowing the metagame for the tournament you are playing is where you want to start.
The metagame can differ widely from a local game store to an Open or Grand Prix. Even within your local scene, the metagame can vary from store to store. If you learn the popular decks for local players, you can tailor your sideboard more effectively than is usually possible at regional or larger tournaments. You can skew your sideboard to the matchups you’ll definitely see. Let’s use the modern format as an example. If your LGS has a bunch of Affinity players, you can load up on artifact hate and removal, even if Affinity decks aren’t dominating the larger Modern metagame. You can make room by trimming other sideboard cards that your deck usually plays but that happen to be less useful against the popular local decks.
Larger events at Opens or MagicFests tend to have enough players to smooth out any local preferences. You can still use local knowledge to metagame side events, if you happen to know that the weekend tour spot is a hotbed of burn decks or something. And once you get to invitational-level tournaments, the fields shrink and specific metagaming becomes possible again.
Learn the Format
Knowing the format is a little bit different than knowing the specific metagame. For smaller constructed formats, the two can be effectively the same. But format knowledge includes the powerful combinations and interactions, the typical tempo and lines of play, that often exist across many decks. And more generally, you need to know the sorts of things that your opponents will be trying to do if you want to sideboard effectively to beat their strategies.
Once you know what is going on in the format, you should focus on the specific holes or weaknesses of your deck. From there you can think about what you want your deck to look like post sideboard in various matchups. That also helps you gauge how many slots are relevant for each matchup. It doesn’t do you much good to put eight pieces of graveyard hate in your sideboard if you can’t afford to remove more than four cards in those matchups.
I generally like to over-saturate my sideboard with cards that will improve my worst matchups. For better matchups, I prefer one to three cards at most. Let’s use a Standard control mirror match as an example this time. Control needs to have a lot of removal in the main deck, which creates many dead cards to sideboard out. Your mirror game ones always come down to drawing the least amount of removal spells. That means you can include ten or more cards in your control sideboard that work well in the mirror. Of course, your removal might find some targets in the opposing sideboard, so you might not need to swap out that many cards. Again, knowing the format will help guide your analysis there—Thief of Sanity is a big part of the current Standard metagame, for example.
Get Flexible
Now I know I use the term flexible a lot, but that’s because flexibility is important in multiple aspects of the game. Magic is a card game with hidden information, so you need to get flexible and stay flexible to compete. Flexibility takes on additional importance in sideboarding because you want to maximize the value you get from each of your fifteen slots.
The main source of flexibility in sideboarding comes from choosing sideboard cards that do things against multiple different decks. You’ll run out of slots filling your board with single-deck hate cards. Consider Modern Grixis Death’s Shadow. The sideboard features cards that are good against multiple decks, like Disdainful Stroke. Disdainful Stroke is good against Amulet Titan, Tron, and any form of control deck. If you used a similar substitute in the form of Negate, you lose the ability to counter major threats like Wurmcoil Engine and Primeval Titan.
Closing Thought
Always be careful to understand the composition of your deck after boarding. You do not want to dilute what your deck is trying to do. Swapping out too many cards can ruin the engine of your deck and leave you too reactive to actually win the game. For example, if you are playing a combo deck, you need the concentrated core of combo cards for your deck to function. Various deck archetypes will have different numbers of available slots in each match. Consider that when you design your sideboard, and don’t be afraid to adapt your sideboard building from deck to deck.
Zack is a SCG grinder with one ultimate goal: getting to the Players Champ. Based out of NYC, you can find him in other cities every weekend trying to hit that goal. When he isn’t traveling he streams. Follow his journey on Twitter!